'02-'05 WJ 4.0 I6 will it bolt into the MJ?

[Unglar]

A friend of mine has a '03 WJ with the 4.0 I6, it looks exactly like the one in my MJ. I understand all the accessories would be a PITA, however is it bolt in? Has anyone tried this?

[terrawombat]

Short answer - Yes

 

Longer answer - You'll need to swap over all of your accessories, obviously, but the engine mounting bosses should all be there. I believe the water pump will be different - I think the WJ fan is attached directly to the waterpump and it's not as simple as just swapping waterpumps since the mounting holes are different between an XJ and WJ waterpump. Also want to check on the exhaust ports, but I think you'll be fine. The later 4.0 I6 used smaller exhaust ports so you should be fine as the MJ exhaust header will completely cover them up.

[JeepcoMJ]

into which of your comanches?

 

 

the high output '92...yes. but you'll probably have to thread the bosses for the cherokee/comanche motor mounts

 

the renix '87...nope. not without a bunch of dicking around.

[Unglar]

into which of your comanches?

the renix '87...nope. not without a bunch of dicking around.

 

Actually I am looking at this for the '87. I was thinking I could swap out everything under the hood and under the dash. I know it would be a major job. I just found a rolled '04 WJ with 67k at a salvage auction in SLC. :brows:

[terrawombat]

the renix '87...nope. not without a bunch of dicking around.

 

I'm curious - what about the '87 Renix will make it difficult to swap in a later model 4.0L? I honestly don't know, that's why I'm asking!

[JeepcoMJ]

the renix '87...nope. not without a bunch of dicking around.

 

I'm curious - what about the '87 Renix will make it difficult to swap in a later model 4.0L? I honestly don't know, that's why I'm asking!

 

you have to swap all accessories, but the renix intake and exhaust ports on the manifolds don't line up, so you really should use the '87 head, or a '91 to '98 exhaust manifold and downpipe. then you have to retrofit the renix throttle body to work, or retrofit the renix TPS to work on the H.O. throttle body.

 

then there's all the vacuum refits.

 

 

 

now, you could do the "full" H.O. swap, but the wiring from a grand cherokee is NOT going to sit in a comanche. there are a bunch of extra things in that wiring that are useless and will make it hard to get things bolted together since you can't install all the optionns the WJ has. you can't use the exhaust manifolds from the WJ without dicking around with custom downpipe.

 

 

to do a high output swap as a full high output swap, you must swap the engine and dash harness swap with all electrical and cooling components.

[75sv1]

I have put in an '03 4.0L from a GC, into my '88 Comanche. I did put a '95 head on it. The problem you might run into is that two of the engine mount bosses on mine were different. One was longer and one was shorter. They were in the same location. The shorter one was easy, I added a spacer. I think it was .916 in length. The other side, I had one of the ears on the engine mount cut and welded to compensate for the extra length on the boss. The engine brackets are cast steel, so the weld easy. At least the welder told me that. Another person who had the same problem, cut down the boss.

Another difference, is the water pump bolt pattern. I don't know how or if it will affect you. It has an additional bolt in the pattern, and there are two holes in different location. I am planning to use the GC accesory drive on that.

There is also a square post or boss on the drivers side. It is for the A/C compressor mounting. I don't think it would affect anything, if you went with an XJ or MJ accesory drive.

I'd probably keep the Intake and Throttle Body. There is a way to wire the Throttle Position sensor for the Renix to use a newer TB.

Tom

[Unglar]

Thanks for the info! It sounds like you used only the block, IF I can get a rolled WJ, my plan is to use everything under the hood. Is there a significant difference between the '01 XJ 4.0 and the '04 WJ 4.0? It would probably be alot easier to use the '01 XJ, I was just trying to find the newest engine I could. Besides, I would still need to replace the puke goat. I don't suppose the WJ tranny would fit an MJ eh?